<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .container {
      width: 300px;
      height: 300px;
      border-radius: 20px;
      border: 1px solid #ccc;
      padding: 50px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .circle{
      width: 50px;
      height: 50px;
      border: 1px solid #ccc;
      background-color: blue;
      border-radius: 50%;
    }
    .circle:first-child {
      align-self: flex-start;
    }
    .circle:last-child {
      align-self: flex-end;
    }
  </style>
</head>
<body>
  <div class="container">
    <div class="circle"></div>
    <div class="circle"></div>
    <div class="circle"></div>
  </div>
</body>
</html>